Adding issue number to commit messages

We have a convention of naming our feature branches like feature/12345-short-description where the 12345 is the number of the issue we are working on. It is also helpful to include that number in the commit message so that it looks something like

[12345] fixed the bugs I introduced

but it is a hassle to copy and paste the issue number each time, so I have automated it with this function that is included in my .profile file.

function gc() {
  message=$1
  if [ $# -ne 0 ]; then
    ticket=`git symbolic-ref --short HEAD | cut -d '/' -f2 | grep -o [\#0-9]* | tr -d "\r\n"`
    git commit -m "[$ticket] $message"
  else
    echo "please supply a commit message"
  fi
}

Now I can just type gc 'fixed the bugs I introduced' and it adds the square brackets and issue number with no interruptions on my part to copy it into the commit message.